Mobile devices such as mobile phones are not only becoming smarter, they are also becoming more aware of their surroundings, so as to provide increasing capabilities and operating modes for their users. For example, a mobile phone may include an optical proximity sensor that can be used to detect different use modes, such as a phone call mode when the mobile phone is held close to a user's head, and a browsing display mode when the mobile phone is held further from the user's head, so as to provide comfortable browsing of information shown on a display of the mobile phone. Since the optical proximity sensor helps the mobile phone to be aware of its surroundings, the mobile phone can save power and extend battery life by automatically dimming the display when the mobile phone is held close to the user's head while operating in the phone call mode, but automatically maintain full display brightness when the mobile phone is held further from user's head, while operating in the browsing display mode.
Similarly, a mobile device, or more generally a computing device, may include a gesture sensor for optically detecting a gesture, such as a hand gesture of a user. A user can control or interact with the mobile device via the gesture sensor for a favorable and intuitive user experience.
Likewise, a mobile device, or more generally a computing device may include an imaging sensor for electronically capturing an optical image. For example, the mobile device can be secured by first recognizing the face of its owner via the imaging sensor before allowing access.
While the foregoing may provide many benefits in making mobile devices aware of their surroundings, and in particular aware of changes in their surroundings, those surroundings may present many challenges to optical designers. Such surroundings can be filled with unwanted optical signals, as well as optical signals of interest. Optics are needed that will collect optical signals of interest, while limiting unwanted optical signals. Further, while there may be some advantages to initially molding optics in liquid form, there is a need to limit bubbles when optics are initially molded in liquid form.